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