In OpenGL NURBs can be drawn using evaluators. But it seems evaluators were removed from OpenGL ES spec to make it light weight. In that case, how can one draw NURBs using OpenGL ES API?
You won't get around implementing the NURBS stuff yourself. Meaning you have to sample the curve or surface at discrete points and thus convert it to an ordinary line strip or triangle set respectively. This can then be drawn with the usual vertex arrays/buffers, which should also be faster than evaluators or the GLU NURBS functions.