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