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