factorplot is an R package that helps visualize pairwise comparisons. It is particularly useful as a post-estimation technique following a (G)LM, multinomial logistic regression or any other multiple comparison procedure done with multcomp. A more thorough discussion of the method and what it produces are here:
David A. Armstrong II. 2013. "factorplot: Improving Presentation of Simple Contrasts in Generalized Linear Models." The R Journal. 5(2): 4--15.
factorplot can be installed from this repository with:
library(devtools) install_github("factorplot", username="davidaarmstrong")