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