How can I visualize TensorRT network graph?

There is no way to do this, because the TensorRT model (engine) is optimized for certain hardware (A specific NVIDIA GPU architecture). It is already "compiled" (similar to coreML mlmodel's are compiled to mlmodelc, where as TensorFlow (or TFLite) models are not "compiled" for specific hardware.

From the NVIDIA forums: https://forums.developer.nvidia.com/t/visualizing-tensorrt-engine/69032

I assume you are asking for something analogous to tensorboard or netron? Unfortunately, I’m not aware a way for TRT.

From the creator of Netron (lutzroeder):

Unless this format is documented not sure much can be done here. Netron has a browser-only version so even if a Python or C++ API existed for supporting non-inference scenarios it wouldn't be useful.

You can still of course visualize the ONNX model right before you create the TensorRT one. TensorRT just needs an optimized model, so I don't expect it to be different.

You can now visualize tensorrt engine graphs using https://github.com/NVIDIA/TensorRT/tree/main/tools/experimental/trt-engine-explorer

It also offers other info about the engine.

Is the goal to visualize it after the compression from onnx/TensorRT? Or just to visualize it in general? You can always just use the keras tool.

I believe you can use a TensorRT model as well with netron, based on this youtube video.