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