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