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