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