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