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