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