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