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