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