PlantUML uses [Graphviz](https://www.graphviz.org/) for his graph visualization. Thus the rendering itself is done automatically for you - that it one of the biggest advantages of using PlantUML.
PlantUML uses [Graphviz](https://www.graphviz.org/) for its graph visualization. Thus the rendering itself is done automatically for you - that it one of the biggest advantages of using PlantUML.
...and also sometimes one of the biggest disadvantages, if the rendering is not what the user intended.