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