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