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