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