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