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