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