The home base of the Satanic Cult is the Retirement Home.
The head of the cult is called The Hooded Leader. At the start of the series, Atticus' father (Atticus Murphy Sr.) fulfills this position. After Atticus beheaded him at the end of the first season, he took up this position himself.
The direct subordinates of The Hooded Leader are the minions. The minions are dressed in red robes and are to obey the Hooded Leader's every command. There are different ranks among the minions, and when given a command, a minion can suborder the command to a lesser minion.
It can be assumed that all the other residents in the retirement home are also part of the satanic cult, but they are not minions and dress like regular senior citizens. They do however seem to fall under the command of the Hooded Leader.