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