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