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