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