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