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