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