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