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