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)(11,18,21,19)(12,23,14,16)(15,20,24,22)(25,26)(27,31)(28,37)(29,35)(30,34)(32,38)(33,40)(36,39)(1,3,5,4)(2,6,8,7)(9,10)(11,19)(12,16)(13,17)(14,23)(15,22)(18,21)(20,24)(25,27,30,32)(26,31,34,38)(28,33,39,35)(29,37,40,36)(1,3,5,4)(2,7,8,6)(9,11,14,20,13,21,12,22)(10,15,23,19,17,24,16,18)(25,28,29,38,30,39,40,31)(26,32,33,37,34,27,35,36)(1,4,5,3)(2,7,8,6)(9,12,13,14)(10,16,17,23)(11,20,21,22)(15,19,24,18)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.