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