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)(11,17,19,14)(12,16,21,23)(18,24,20,22)(27,33)(31,35)(34,39)(37,40)(9,11,13,19)(10,14,15,17)(12,20,21,18)(16,24,23,22)(26,30)(27,34)(28,36)(31,35)(32,38)(33,39)(2,5)(6,8)(25,26,28,30,29,32,36,38)(27,35,34,40,33,31,39,37)(1,3,4,7)(2,6,5,8)(10,15)(14,17)(16,23)(22,24)(27,33)(31,35)(34,39)(37,40)(9,12,13,21)(10,16,15,23)(11,18,19,20)(14,22,17,24)(25,27,36,39,29,33,28,34)(26,31,38,40,32,35,30,37)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.