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