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