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