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