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