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