One vertex per element, one color per generator, with an edge from x to x·s.
(5,8)(9,10)(11,16)(12,17)(13,22)(14,18)(15,19)(20,23)(21,24)(25,26,29,33)(27,30,35,39)(28,31,36,32)(34,37,40,38)(1,2,4,6)(3,5,7,8)(9,11)(10,15)(12,19)(13,21)(14,20)(16,22)(17,23)(18,24)(25,27,29,35)(26,30,33,39)(28,34,36,40)(31,37,32,38)(1,3)(2,5)(4,7)(6,8)(9,11)(10,16)(12,21)(13,19)(14,20)(15,22)(17,24)(18,23)(26,31)(28,36)(30,37)(32,33)(34,40)(38,39) involution — undirected(9,12,14,13)(10,17,18,22)(11,19,20,21)(15,23,24,16)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.