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