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