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