General Prefixes:
* Auto- (self): autograph, autographed
* Bio- (life): biograph, biography
* Chrono- (time): chronograph
* Digi- (digital): digigraph
* Electro- (electricity): electrograph
* Geo- (earth): geograph, geography
* Micro- (small): micrograph
* Nano- (extremely small): nanograph
* Photo- (light): photograph
* Tele- (distance): telegraph
Specific to Graphing:
* Bar-: bar graph
* Line-: line graph
* Pie-: pie graph
* Scatter-: scatter graph
* Histo-: histogram
The best prefix will depend on the specific meaning you want to convey. For example, "autograph" means a signature written by oneself, while "telegraph" means a device for sending messages over long distances.