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