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