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