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