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