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)(26,30)(27,33)(28,35)(39,40) involution — undirected(2,5)(6,7)(10,14)(15,17)(16,20)(23,24)(25,26,29,30)(27,31,33,38)(28,36,35,32)(34,40,37,39)(1,2)(3,6)(4,5)(7,8)(11,18)(15,17)(19,21)(23,24)(25,27,29,33)(26,31,30,38)(28,34,35,37)(32,39,36,40)(1,3,4,8)(2,6,5,7)(9,11,13,18)(10,15,14,17)(12,21,22,19)(16,24,20,23)(25,27)(26,31)(28,37)(29,33)(30,38)(32,40)(34,35)(36,39)(9,12)(10,16)(11,19)(13,22)(14,20)(15,23)(17,24)(18,21)(25,28)(26,32)(27,34)(29,35)(30,36)(31,39)(33,37)(38,40) involution — undirected(9,10)(11,15)(12,16)(13,14)(17,18)(19,23)(20,22)(21,24)(25,26)(27,31)(28,32)(29,30)(33,38)(34,39)(35,36)(37,40) 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.