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