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