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