The address is
730 N Chestnut
Olathe, KS 66061
The Sexton used to have an office there. However, I believe the position has been eliminated. The cemetery is run by the City of Olathe. The phone number for the Sexton's office is not listed in the current phone book.
The county genealogical society has published a cemetery index for this cemetery. I will take a look the next time I am at the library. I will also see if any others with the same surname are buried there.
Otherwise, you can call the general information number for the city,
Overland Park, KS