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