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