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