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