Hello......the most common leak is the power steering pressure hose ,this hose screws into the pump and goes to the steering box.
If the hose is not wet from oil i recommend to wash the pump with some degreaser and then run the engine and turn the steering wheel a few times.
Look for leak from front pump seal or the reservoir to pump seal.(big o'ring around the pump)
There is also the return line/hose from box to the reservoir ,it has a clamp on pump side.It usually does not leak unless it rusts.
The oil on top of pump is because the system is getting air through the leak and when you stop the engine it over flows the reservoir.
Let me know. Accept my answer if i have helped.
I am only the tech ,you will need to contact customer service.