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