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