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)(11,17)(12,20)(13,16)(14,19)(15,21)(18,23)(22,24)(25,26,28,33,30,32,29,34)(27,35,37,40,36,31,38,39)(2,6)(3,4)(7,8)(9,11)(10,14,16,22)(12,19)(13,18)(15,17,20,23)(21,24)(25,27,29,37,30,36,28,38)(26,31,34,39,32,35,33,40)(1,3,5,4)(2,6,8,7)(11,18)(14,22)(17,23)(19,24)(27,36)(31,35)(37,38)(39,40)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.