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