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