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