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