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