One vertex per element, one color per generator, with an edge from x to x·s.
(6,9)(10,12)(14,17)(15,19)(21,22)(23,34)(24,30)(25,29)(26,32)(27,31)(28,33)(35,36) involution — undirected(1,2,3,4)(5,6,8,9)(7,10,11,12)(13,14,16,17)(15,18,19,20)(21,23,26,25,28,24,27,35)(22,29,31,34,33,36,32,30)(2,4)(7,11)(10,12)(13,15)(14,18)(16,19)(17,20)(21,24,28,23)(22,30,33,34)(25,27,35,26)(29,31,36,32)(5,7,8,11)(6,10,9,12)(15,19)(18,20)(21,25,26,24,28,35,27,23)(22,30,31,29,33,34,32,36)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.