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