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