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