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