edges=Flatten[Rest[NestList[Union[Flatten[Thread[#->WordData[#,"Synonyms","List"]]&/@Last/@#]]&,{""->"network"},2]]];

style={VertexLabels->"Name",ImagePadding->30,ImageSize->500,GraphStyle->"ThickEdge",EdgeStyle->Directive[Opacity[0.3],Thickness[0.015],Hue[0.12,1,.7]]};

Graph[edges,style]