Several softwares are available for drawing piper diagram. E.g. AqUA (Rockware), Aquachem, Geochemist workbench etc. However, one can easily generate piper diagram using Excel. It is simple. Go through the attached papers and I am sure you will do it easily. What is more important is interpretation of piper plot. Go through the different interpretations in the published literature. I would be useful to explain natural geochemical processes than anthropogenic processes.
Thanks for your answers, I search in Blog's and I found a small program as GW_Chart. But it can be using for only Piper diagram. http://water.usgs.gov/nrp/gwsoftware/GW_Chart/GW_Chart.html
You can use the EasyQuim program. It has been developed by the Hydrogeology Group of the Technical University of Catalonia (Spain). It works perfectly and it is for free!. The program makes some calculations such as units conversion (ppm to meq/L), balance errors or ionical relationships, but also plots Piper, Schöeller-Berkaloff, SAR (Salinity) and Stiff diagrams. You can download the program from the following link https://h2ogeo.upc.edu/software/EASY_QUIM5.0_v2012.exe
You can draw it in several different ways. The most practical software for drawing Piper diagram is Aquachem, you can download it for free; it is simple to use. There is so many softwares for drawing triangle diagrams. You can separate Piper diagram into two triangles and draw them using triangle plotting softwares. The last way is plotting manually. This way is not complicated but is time consuming.
Programming in R has Gibbs graphs and I think it has instructions for making a Piper graph
However, if you want to represent positions on a Piper chart only, you can use an Edgeworth box which is easy to construct on an Excel sheet because the internal angles are right. The same plotting results are achieved as in a Piper plot.