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