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