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