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