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