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