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