I used the 3D paint tool to paint over a NURBS sphere. I'm basically drawing a face on a simple character.

I saved it in the middle of painting, and exited Maya. When I got back to working on it, the paint was gone... It's now just a sphere with a regular lambert grey color. However, when I rendered the scene, the paint is still there. I just can't see it on my screen. I've already pressed 6 to get the textures on screen, but I still cannot see the painted face. It remains grey, and I can only see my past work when I render. This problem is also preventing me from continuing my work because I can't see what I'm doing, nor is it allowing me to paint over it. There is an error that says "Some surfaces have no file texture assigned to the current attribute", but there is
a file texture, as can be seen when rendered.

How do I see my 3D paint work on screen and continue working on it?