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