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