Luis,
I think I understand that you're concerned about viewing meshed bodies in the pre-processing phase, not the post-processing. The previous link that I provided was only for post-processing, as you can see each meshed body and even cut those meshed bodies to view stress results or whatever results you have pre-determined.
I think Mats gave you the best explaination. This is on my list of Product Ideas, to have the same meshing capabilities in Creo Simulate as they do in StressCheck. StressCheck will do exactly what you're asking for, because each body in StressCheck has it's own independent mesh record before even assigning material properties. You just select the desired mesh record (or elements sets as they call it) and that's what you will see in the GUI, the desired meshed body.
However, if you're concerned about the meshed body being invalid, Creo will give you a report (diagnostic tool) that will show you the troubled elements, if any, during the automesh phase.
Whenever I had to build large assemblies, I meshed each body independently before putting them into the final assembly, so when I had to automesh the entire assembly, I knew that each body was valid, but I still had to mesh the assembly to see how well the components meshed for muti-body nonlinear contact.