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