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