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