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