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