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