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