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