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