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