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