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