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