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)(11,19,22,15)(12,18,14,16)(20,24,21,23)(2,5)(6,7)(9,11)(10,15)(12,21)(13,22)(14,20)(16,23)(17,19)(18,24)(25,26,29,32)(27,33,35,40)(28,36,38,31)(30,37,39,34)(10,16)(11,20)(12,14)(17,18)(21,22)(23,24)(25,27,29,35)(26,30,32,39)(28,37,38,34)(31,40,36,33)(1,3,4,8)(2,6,5,7)(9,12,13,14)(10,16,17,18)(11,21,22,20)(15,23,19,24)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.