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