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