We examine a variant of hypergraphs that we call linear hypergraphs, with the aim of creating a sound and complete graphical language for symmetric traced monoidal categories (STMCs). We first define the category of linear hypergraphs as a full subcategory of conventional (simple) hypergraphs, in which each vertex is either the source or the target of exactly one edge. The morphisms of a freely generated STMC can be then interpreted as linear hypergraphs, up to isomorphism (soundness). Moreover, any linear hypergraph is the representation of a unique STMC morphism, up to the equational theory of the category (completeness). This establishes linear hypergraphs as the graphical language of STMCs. Linear hypergraphs are then shown to form a partial adhesive category which means that a broad range of equational properties of some STMC can be specified as a graph rewriting system. The graphical language of digital circuits is presented as a case study.