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