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