The closest I came to a diagram was a breakdown, but they don't look like the actual internal pump parts are available, Just some of the inside parts and the outer shell parts. Maybe since failure of one part of the system can cause failure of other parts, don't actually expect it to be repaired. Meaning a motor failure will destroy the pump and if the pump fails and the system isn't flushed properly the debris can damage the new pump.
Maybe able to determine who made the actual hydro unit and see if they offer a more extensive parts diagram. Why do I have this thought in the back of my head that this is a Parker brand system. Very limited information offered by the company and if you do find parts they are very expensive, sometimes to the point that a single part can exceed the close of the entire unit. Like the entire drive assembly may be $2000 but they will want $2500 for the pump by itself.