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