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