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