Can anyone recommend me a tool to easily draw a network diagram?
Perhaps this one…
https://app.diagrams.net/
We use https://lucidchart.com for our network engineering team which has a free version.
Here are some examples of drawings i’ve done with LucidChart:
I use yED https://www.yworks.com/products/yed (freeware).
If the basic icon set isn’t enough you can add more, e.g. https://github.com/danger89/yEd_cisco_network_icons or create your own.
What MikroTik machines do you have?
Your description looks more like an advertisement than a normal comment…