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