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)(13,14,18,24)(20,23,22,21)(25,26,30,32)(27,31,35,38)(28,33,37,39)(29,34,36,40)(1,2)(3,7)(4,8)(5,6)(9,11,15,12)(10,16,17,19)(13,20,18,22)(14,21,24,23)(25,27,30,35)(26,31,32,38)(28,36,37,29)(33,40,39,34)(10,17)(14,24)(16,19)(21,23)(26,32)(27,35)(29,36)(33,39) involution — undirected(1,3,5,4)(2,7,6,8)(9,12,15,11)(10,16,17,19)(13,20,18,22)(14,23,24,21)(25,28,30,37)(26,33,32,39)(27,29,35,36)(31,34,38,40)(1,4,5,3)(2,8,6,7)(9,13,15,18)(10,14,17,24)(11,20,12,22)(16,21,19,23)(25,26)(27,31)(28,33)(29,34)(30,32)(35,38)(36,40)(37,39)(9,14)(10,18)(11,21)(12,23)(13,17)(15,24)(16,22)(19,20)(25,29)(26,34)(27,28)(30,36)(31,33)(32,40)(35,37)(38,39) involution — undirectedA 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.