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