One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6)(7,10)(8,11)(9,12)(13,17)(14,18)(15,19)(16,20)(21,22)(23,32)(24,31)(25,30)(26,29)(27,34)(28,33)(35,36) involution — undirected(1,2,3,4)(5,7)(6,10)(8,15)(9,13)(11,19)(12,17)(14,16)(18,20)(21,23,25,34)(22,27,30,32)(24,35,26,33)(28,29,36,31)(7,13)(10,17)(14,15)(18,19)(21,23)(22,28)(24,33)(25,34)(26,35)(27,31)(29,32)(30,36) involution — undirected(5,8,9,16)(6,11,12,20)(7,14,13,15)(10,18,17,19)(6,12)(10,17)(11,20)(18,19)(21,24,25,26)(22,29,30,31)(23,33,34,35)(27,28,32,36)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.