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