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