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