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