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