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