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