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