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