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