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