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