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