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