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)(11,16,21,17,12,22,23,24)(25,26,29,32,30,33,28,34)(27,31,37,39,36,40,35,38)(1,3,4,8)(2,5,6,7)(9,11,15,12)(10,16,20,22)(13,23,14,21)(17,18,24,19)(25,27,29,37,30,36,28,35)(26,31,32,39,33,40,34,38)(9,12,15,11)(10,17,20,24)(13,23,14,21)(16,18,22,19)(26,32)(27,35)(28,29)(33,34)(36,37)(38,39)(2,6)(5,7)(9,13,15,14)(10,18,20,19)(11,21,12,23)(16,17,22,24)(26,33)(27,36)(32,34)(35,37)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.