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