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