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