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