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