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