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