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