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