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