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