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