Network map node image

Please help me change the node image in the network map and edge labelled text rotation diagonally to keep it on the line, about the screenshot. I want to change the node images according to their type manually or dynamically.
I tried using the code below in config.php but failed.
“nodes”: {
“id”: 21,
“shape”: “image”,
“image”: “images/custom/icons/switch-l2.svg”,