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