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