Yep -- painting is your option. There's no quick way for that ship since nobody has made decals or masks for it.
You could trace a pattern onto the ship, scan it, draw it in a vector app, then take it to a sign company and have them cut vinyl masks. That's a lot of work, and you need to make sure you draw it according to the sign company's specs.
A better option would be to go the Paul Olsen way and cut rectangular masks and keep spraying light rectangles of color until it looks right. You could use post-its, each with a different-sized rectangle hole inside. For the primary hull, you'd have to cut a series of real aztec shapes and wedge segments, either from vinyl or plastic for durability. As Club Tepes wrote, you might be able to use Aztec Dummy-like templates there, but there are no guarantees.