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)(11,17,18,16)(12,21,23,13)(19,24,22,20)(25,26,31,34)(27,30,29,32)(28,33,38,40)(35,37,36,39)(2,5)(6,7)(10,15)(13,21)(16,17)(20,24)(27,29)(30,32)(35,36)(37,39) involution — undirected(1,2)(3,6)(4,5)(7,8)(11,18)(16,17)(19,22)(20,24)(25,27,31,29)(26,32,34,30)(28,36,38,35)(33,37,40,39)(1,3,4,8)(2,6,5,7)(9,11,14,18)(10,16,15,17)(12,22,23,19)(13,20,21,24)(25,28)(26,33)(27,35)(29,36)(30,37)(31,38)(32,39)(34,40)(9,12)(10,13)(11,19)(14,23)(15,21)(16,24)(17,20)(18,22)(25,29,31,27)(26,30,34,32)(28,35,38,36)(33,39,40,37)(9,13)(10,12)(11,20)(14,21)(15,23)(16,22)(17,19)(18,24)(25,30)(26,27)(28,37)(29,34)(31,32)(33,35)(36,40)(38,39) 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.