In the service industries like hospitality or airlines, heavy emphasis is laid on the grooming and deportment. Employees are given proper training on these subjects.
However, if you wish to take action for not adhering to the standards of the hotel that it follows, then you may conduct the training and obtain undertaking from the employee that he/she has understood the grooming policies of the hotel and he/she is liable for the disciplinary action if it is not adhered to.
At the time of actual execution, if you find some employee's grooming is not as per the standard, then you may write letter to HR about violations of the grooming standards. Let them take action as they deem fit. In case, if you report directly to the General Manager of the hotel then you may send weekly report on grooming to him/her. How to handle such cases, becomes his/her prerogative.
As a training coordinator, you can do the audit of the operations. However, taking disciplinary action is out of your purview.