Step 1: Understand the request
The user is asking for a free AI tool for graphing or drawing.

Step 2: Identify available options
There are several free AI tools available for graphing or drawing、Some popular options include online platforms and software that utilize AI for generating graphs or artwork.

Step 3: List potential tools
Some potential tools include:
Desmos: A popular online graphing calculator that can be used for creating graphs.
GeoGebra: An interactive mathematics software that can be used for graphing and geometry.
Deep Dream Generator: An online tool that uses AI to generate surreal artwork from images.
Prisma: An app that uses AI to transform photos into artworks in the style of famous artists.
AutoDraw: A tool that uses AI to help users draw simple diagrams and illustrations.

Step 4: Specify the most relevant tool for 作图 (graphing or drawing)
For the term 作图 which translates to drawing or graphing, tools like Desmos or GeoGebra are more relevant for mathematical graphing, while AutoDraw is more suited for simple drawings.

Step 5: Provide a recommendation
For a user looking for a free AI tool for graphing, Desmos is a highly recommended option due to its powerful graphing capabilities and ease of use.

The final answer is: $\boxed{Desmos}$