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