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