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