Use Vennerable package in R. It can display venn diagram for upto 9 sets. It can also produce weighted venn diagrams. To install it,
install.packages("Vennerable", repos="http://R-Forge.R-project.org";)
Here is command for 3 sets
vennD=Venn(SetNames = c("Samp1", "Samp2","Samp3"), Weight=c(`100`=x,`010`=x,`110`=x,`001`=x,`101`=x,`011`=x,`111`=x))
x
is the any number corresponding to set (e.g. 111
means common to all samples)
plot(vennD, doWeights = FALSE, type = "circles")
Development page: https://r-forge.r-project.org/R/?group_id=474