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