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