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