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