"The Dragon spacecraft design is structurally identical for both the cargo and crew configurations, the chief differences being the thrusters, internal outfitting, and some other subsystems. For cargo launches, the inside of the capsule is outfitted with a modular cargo rack system designed to accommodate pressurized cargo in standard sizes. For crewed launches, the interior will be outfitted with crew couches, controls with manual override capability, and upgraded life support. Keeping the cargo and crewed versions of Dragon similar minimizes the design effort. "
NASA - Space Exploration Technologies (SpaceX)