First get phrase appearance pattern on positive labeling (if not directly passed) and then calculate similarity matrix of how they are similar to each other.
make.similarity.matrix(result)An textreg.result object or a matrix from make.appearance.matrix
Warning: for 'negative weight' phrases this method does not do well since it ignores negative documents.
Other Phrase Vizualization: cluster.phrases,
make.appearance.matrix,
make.phrase.correlation.chart