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