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)(11,19)(12,14)(13,16)(15,17)(18,23)(20,24)(21,22)(25,26,29,30)(27,33,35,31)(28,32,36,37)(34,39,40,38)(1,3)(2,5)(4,7)(6,8)(9,11,15,13)(10,16,17,19)(12,20,23,22)(14,21,18,24)(26,30)(31,33)(32,37)(38,39)(1,4,6,5)(2,3,7,8)(10,17)(14,18)(16,19)(21,24)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(1,5,6,4)(2,3,7,8)(9,12)(10,18)(11,20)(13,22)(14,17)(15,23)(16,24)(19,21)(25,26)(27,31)(28,32)(29,30)(33,35)(34,38)(36,37)(39,40)(9,13,15,11)(10,19,17,16)(12,22,23,20)(14,24,18,21)(25,27,29,35)(26,31,30,33)(28,34,36,40)(32,38,37,39)(1,3)(2,4)(5,7)(6,8)(9,14,15,18)(10,12,17,23)(11,21,13,24)(16,20,19,22)(25,28,29,36)(26,32,30,37)(27,34,35,40)(31,38,33,39)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.