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