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