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