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