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