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