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