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