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