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