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