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