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