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