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