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