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