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