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