The conceptual framework will serve as a quick, easy glance to your entire LR section. It is like the front page of your book, which is the first step to hold the interest of your reader, to read any further. And yes, it is best represented through a diagram, using simple blocks and arrows, showing the inter-relations between the variables under study.This would in fact help you, yourself at your analysis and discussion stage, by putting your results in line with the proposed framework.