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