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