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