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