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