One vertex per element, one color per generator, with an edge from x to x·s.
(1,2) involution — undirected(7,8,11,14)(9,15,17,12)(10,13,18,20)(16,21,22,19)(23,24,27,31)(25,33,26,29)(28,37,36,32)(30,34,38,35)(3,4)(5,6)(7,9,11,17)(8,12,14,15)(10,16,18,22)(13,19,20,21)(23,25,27,26)(24,29,31,33)(28,34,36,35)(30,32,38,37)(4,6)(7,10)(8,13)(9,16)(11,18)(12,19)(14,20)(15,21)(17,22)(23,26,27,25)(24,30,31,38)(28,34,36,35)(29,32,33,37)(10,18)(13,20)(16,22)(19,21)(25,26)(29,33)(30,38)(34,35) involution — undirectedA 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.