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