design divides the living space into 7 decks, labeled A to G, from the bottom-up

ISS found a need for 2+ hours of exercise per day to avoid bone and muscle loss. Multiplied by 100 people, that requires 10 exercise machines. Note that several of them are mounted on the walls.

Making full use of walls and ceilings for living space is a theme of this design, since there's no "down" in zero-G.

The airlock allows access to the outside of the ship during flight, in case of a need to make inspections or minor repairs, and to support landing in places without pre-existing ground infrastructure.

25 rooms on each deck, with 2 people per room.

Rooms are separated by removable walls (shown installed in the Deck C rendering).

Walls will be removed during launch and landing (as shown in the Deck B rendering).

Groups traveling together may want to remove the wall between their adjoining cabins.

Seats are positioned radially for acceleration (as shown in the 1st Deck B rendering) and paralleled during EDL (as shown in the 2nd Deck B rendering). The position / orientation of the seats can be changed automatically, with enough range of motion to account for the ship's direction vector change during EDL.

After launch, the seats can be removed, disassembled, and stowed in the area on Deck A.

Each passenger will have two pieces of carry-on luggage, 0.5 x 0.5 x 0.2m in size, 20 kg max.

Carry-ons will be stored in the ceiling of each cabin.

Only cabins on the leeward side of the ship will have small windows.

Passengers sleep on the walls (in simple sleeping bags, as on ISS), to ease entry and exit while one or the other is asleep.

Passengers will sleep in two shifts, to make more room available per person on non-cabin decks when people are awake.

Passenger's checked luggage is stored on the outside of the shelter, in a layer 0.7m thick.

Each passenger will have 1.0m3 of checked luggage, in several pieces, weighing 250kg max.

The inside of the storm shelter consists of a 12.5cm layer of water, packaged in plastic containers that can be removed.

Water can be removed during the flight and used for cooking, and replaced after processing.

The ship will have a closed-cycle water purification system, similar to ISS (including urine).

Some of the interior storage layer will also be available for food.

During a solar storm, all 100 passengers will need to be in this area.

By nature of its position, the shelter will also provide some additional shielding for the cabin areas.

Self-serve food area.

Food storage and dispensing mechanisms will be loaded by the crew before each meal, to prevent hoarding and similar potential social problems.

Several vertical posts are available in this area, as a place for people to be able to temporarily attach things they're holding to a fixed location (tables don't work in zero-G).

Removable walls here can be used to change the layout of these spaces to suit passenger preferences.

Deck F has a few toilets.

Large video monitors will be available in these areas for shared movie viewing and the like (everyone is also assumed to have their own personal laptop).

Both decks have a view through the large window on the leeward side of the ship.

More speculative internal layouts of Starship by SpaceX fans: