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