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