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