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