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