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