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