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