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