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