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