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)(27,35)(28,33)(29,40)(30,36)(31,37)(32,39)(34,38)(1,2)(3,7)(4,6)(5,8)(12,19)(16,22)(18,23)(20,24)(25,27)(26,32)(28,38)(29,36)(30,34)(31,39)(33,40)(35,37) involution — undirected(1,3)(2,5)(4,8)(6,7)(10,15)(11,17)(16,22)(18,23)(25,28,31,36)(26,33,37,30)(27,38,39,29)(32,40,35,34)(2,6)(5,7)(9,11)(10,13)(12,18)(14,17)(15,21)(16,20)(19,23)(22,24)(25,29)(26,34)(27,28)(30,35)(31,38)(32,33)(36,39)(37,40) 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)(25,27)(26,35)(28,38)(29,36)(30,40)(31,39)(32,37)(33,34) involution — undirected(1,3)(2,7)(4,8)(5,6)(9,13)(10,11)(12,20)(14,21)(15,17)(16,18)(19,24)(22,23)(25,30,31,33)(26,36,37,28)(27,34,39,40)(29,35,38,32)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.