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