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