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