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