Cyclic Subgroup Graph of a Group

A cyclic subgroup graph of a group $G$ is a graph whose vertices are cyclic subgroups of $G$ and two distinct vertices $H_1$ and $H_2$ are adjacent if $H_1\le H_2$, and there is no subgroup $K$ such that $H_1<K<H_2$. M.Tărnăuceanu gave the formula to count the number of edges of these graphs. In this paper, we explore various properties of these graphs.