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)(11,13)(12,17)(14,18)(15,19)(16,22)(20,23)(21,24)(25,26)(27,33)(28,31)(29,32)(30,35)(34,39)(36,38)(37,40)(1,2)(3,4)(5,7)(6,8)(9,11)(10,16)(12,20)(13,19)(14,21)(15,22)(17,18)(23,24)(25,26,29,32)(27,30,35,33)(28,31,36,38)(34,37,40,39)(1,2)(3,4)(5,7)(6,8)(9,12,15,21)(10,17,19,24)(11,20,22,14)(13,23,16,18)(25,26)(27,30)(28,31)(29,32)(33,35)(34,37)(36,38)(39,40)(1,3,5,8)(2,6,7,4)(9,12)(10,17)(11,20)(13,23)(14,22)(15,21)(16,18)(19,24)(25,27)(26,30)(28,34)(29,35)(31,37)(32,33)(36,40)(38,39)(1,2)(3,6)(4,8)(5,7)(9,13,15,16)(10,11,19,22)(12,23,21,18)(14,17,20,24)(25,28,29,36)(26,31,32,38)(27,34,35,40)(30,37,33,39)(1,4,5,6)(2,3,7,8)(9,14,15,20)(10,18,19,23)(11,21,22,12)(13,24,16,17)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.