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