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