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