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