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