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