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