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