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