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