Organizing Committee Member would be perfectly acceptable in English. However, long titles are not often used on name tags/badges, so you might want to shorten it to Organizer, or perhaps Moderator. Sometimes, this role may be referred to as Referee, but I've encountered objections to that because conferences are not sporting events.

Staff is not insulting or demeaning, unless you're thinking of confusion with the people who manage the facility (e.g., the people you talk to when a lightbulb is out).

Organizing Committee Member would be perfectly acceptable in English. However, long titles are not often used on name tags/badges, so you might want to shorten it to Organizer, or perhaps Moderator. Sometimes, this role may be referred to as Referee, but I've encountered objections to that because conferences are not sporting events.

As @JayA.Little notes in the comments, Coordinator is also a valid possibility.

Staff is not insulting or demeaning, unless you're thinking of confusion with the people who manage the facility (e.g., the people you talk to when a lightbulb is out).