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