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