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