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