Embeddings of (proper) power graphs of finite groups
  The (proper) power graph of a group is a graph whose vertex set is the set of all (nontrivial) elements of the group and two distinct vertices are adjacent if one is a power of the other. Various kinds of planarity of (proper) power graphs of groups are discussed. 
Alireza Doostabadi and Mohammad Farrokhi Derakhshandeh Ghouchan
math.GR