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