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