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