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