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