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