You want to use an Eigenmode simulation, be sure to understand Bloch's theorem and periodic boundary conditions before you proceed. I've previously written up a summary (for planar structures) at https://www.edaboard.com/threads/265560/#post1140645
Sorry, your question seemed to imply that you were seeking to understand how to plot the dispersion of the waveguide. I'm not too familiar with cylindrical waveguide design, but I'm sure there are great resources on the internet or textbooks such as Pozar or Balanis.