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