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