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