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