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