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