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