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