Would it be possible for you to attach a copy of your illustration? What type of graph are you working with? If it is a vertical bar graph, the bars could probably all be moved over closer to the vertical axis. Depending on the type of graph, this may not be possible. At the present time, the guidelines for graphs suggest that the label for the horizontal axis be aligned with the first value (which, as you suggested, is "none"). There are no definitive rules for tactile graphics, just guidelines, and each graphic must be considered individually as to what works best. Sometimes even the overall size of the graphic will make a difference in how I handle it.
Hope this helps ... if not, it would still be good to see a copy of the image in order for me to assist you.
Thanks for posting your question.