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