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