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