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