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