Structurizr
Structurizr is a “models as code” tool designed for the C4 model - you write Structurizr DSL to create multiple software architecture diagrams from a single model.
Structurizr’s rich interactive diagrams with a customizable notation and prebuilt themes for Amazon Web Services, Microsoft Azure, and Google Cloud Platform allow teams to tailor visual styles to their needs. Structurizr brings software architecture to life, making complex systems understandable for everyone from developers and architects to executives and stakeholders. The as code approach is version control friendly, supporting traditional Git collaboration workflows. A wide variety of compatible community tools are also available.
Structurizr was created by the author of the C4 model, is free and open source, and remains the reference implementation, making it the best choice if you are looking for compliance and compatibility with the C4 model.