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