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