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