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