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