Mea culpa, I was using the wrong terminology. Let's begin again with the actual wording.
You are correct in that there is nothing specific stating that a government employee cannot exercise their own personal religious freedom. However in their official capacity they cannot do anything that would be perceived as an endorsement of any specific religion.
In order to make this simple let's use an example. Assume that there is a new governor elected in your state. One day he converts to Satanism. He then goes to your State house and says that he will give an opening prayer at the beginning of the session. His prayer consists of an endorsement of satanism and calls on everyone in the legislature to convert to satanism. Is he within his rights to use the power of his office to endorse satanism and convert others to his beliefs?
so if I say a prayer am I endorsing my religion or am I worshiping god? if I wear an Armani suit to work am I endorsing Armani or am I abiding by the proper dress code? if I chose to kiss another man in public am I endorsing homosexuality or am I displaying affection to my partner? how does a document which specifically says Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof
become interpreted as a prohibitive statement? and again a government that goes to the trouble of including such an expression of freedom become a document that denies the employees of that government those exact freedoms?