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