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