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