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