Classifying job titles
I'm surprised you got 80% accuracy and think you will have to do some labeling if you want to improve. Even people have problems with this! For example:


Sales Executive - executive can be misleading, this might have been called "Salesman" 50 years ago
VP at a technology company vs VP at a bank. In the latter case, VP is more of an honorific and might not include any actual management.


If you don't want to mass label data, I would try to assign weights to common words that are featured in titles. For example, replace senior/junior with +1 and -1 in a "seniority" value. If you do that for the top 100 words, I bet it will help over a totally unsupervised approach.