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