A CATIA CATPart file is a 3D model of the part that probably does not include dimensions and notes as you would find on a drawing. If I understand your question, the answer is you cannot view a 3D CATPart as a 2D drawing.
But, you have several options, assuming you have CATIA software:
you could look at it in 3D and rotate/zoom, measure various lengths, etc.
or you could quickly create a new drawing based on the 3D geometry, but you would have to add your own dimensions and notes.