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