the only arcpy access to graphing is here Graph—Help | ArcGIS for Desktop
If you want a python solution, then recent installs of arcmap include matplotlib which offers huge capabilities and integrating with gis data is a breeze matplotlib: python plotting — Matplotlib 1.5.1 documentation
I already built some code, before realizing you could not automate xml export from graph, to parse the data from the xml export to analyze the topographic profile. This code uses ElementTree along with Matplotlib but I wasn't wanting to change the code since the xml export comes out formatted really nice. I hopping for a quirky work around for this solution.