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