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