Dayton, Indiana is right by Interstate 65 halfway between Chicago and Indianapolis.  You most likely will come in from Interstate 65 and take exit 168.  It will be the "Dayton/Lafayette, Highway 38" exit. You will turn to whichever way points to Dayton.   You'll go by a BP gas station (on your left) and go pretty much through the whole tiny town when you will see the large cemetery on your left.  Turn in there.  Below is a map of the area...

  Shannon's grave is in the back of the cemetery.  It's not all the way in the back next to the fence but 20 feet from that and in the center.  It is right by a sign that says "No Drive."  You should park right by that sign.  The cemetary is open 24 hours a day 7 days a week.