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