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