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