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)(23,31,34,36)(24,28,25,29)(27,32,35,33)(2,4)(5,8,10,9)(6,12,13,14)(7,16,17,18)(11,19,15,20)(21,23,26,34)(22,27,30,35)(24,33,25,32)(28,36,29,31)(6,13)(11,15)(12,14)(19,20)(21,24,26,25)(22,28,30,29)(23,32,34,33)(27,31,35,36)(5,9,10,8)(6,14,13,12)(7,16,17,18)(11,19,15,20)(22,29)(24,25)(27,31)(28,30)(32,33)(35,36)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.