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