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