A remote annunciator must be provided to operate outside of the generating room in a location readily observed by operating personnel at a regular work station. However, the panel itself is not required to be at a 24/7 monitored station. You can place the panel somewhere else, as long as it’s remote from the generator. If the location you chose to place the annunciator is not monitored 24/7, you will need to install an audible and visible trouble indicator (clearly labeled for the generator annunciator) at a 24/7 monitored location so they know to go look at the panel if signaled.
If a provider is installing a new generator or undergoing a major upgrade they would need to follow the 2011 National Fire Protection Agency (NFPA) 70, 2010 NFPA 110, 2012 NFPA 99 - otherwise they would follow the code when their generator was installed. The requirement for a remote annunciator at an attended location can be tracked back to 1965.