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)(25,26,29,32)(27,30,34,37)(28,31,35,38)(33,39,40,36)(9,11,13,19)(10,14,15,23)(12,21,22,18)(16,24,20,17)(25,27)(26,30)(28,33)(29,34)(31,36)(32,37)(35,40)(38,39)(2,5)(3,8)(6,7)(25,28)(26,31)(27,33)(29,35)(30,36)(32,38)(34,40)(37,39) involution — undirected(10,15)(14,23)(16,20)(17,24)(27,34)(30,37)(33,40)(36,39) 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.