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