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