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