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