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