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