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