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