Of course there are lots of diagrams you can use to show testing scope and progress. Years ago I worked on large projects that mapped test coverage in different test areas. This made it easy to see blockages and to compare progress. And the managers were always looking for a peak in new bug reports–Then they could say we’re almost finished.
The latest MoT Weekly Newsletter links to the Testcover site with pairwise coverage maps. The idea is to take a pairwise test design and map the pairs to their test cases. If all the pairs are covered, there is at least one test case for each pair. And you can see which test case covers each. Pairs without test cases are not covered. (They may be excluded by constraints.) This type of map shows the scope of the test design, so you can adjust test coverage before starting.