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