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