Format: 

Title of Play. By Firstname Lastname, directed by Firstname Lastname, Production company, Date of performance, Theater, City. Performance.

Examples: 

The Crucible. By Arthur Miller. Dir. Bonnie Meath-Lang. NTID Performing Arts. Robert F. Panara Theatre, Rochester. 17 Feb. 2006. Performance.

In-text: (The Crucible)

Notes: 

You may include any contributors you deem necessary such as the director(s), librettist(s), composer(s), and performer(s). List contributors between the title of the play and the production company and precede all names with an appropriate function label (e.g. directed, performed). If you wish to emphasize the contributions of a specific individual such as the director or actor, begin the citation with that person's name (MLA 24). End your citation with the word Performance to indicate that you viewed a live performance of the play and not the published script (MLA 52).

Source:
MLA - pg 50