Just go to Kuala Besut, either by bus direct, or by plane to Kota Bharu + teksi/grab.
From Kuala besut you take speedboat. They usually land at Coral beach jetty. You will either have to ask them to make a stop in Orang Hutan camping area, or arrange for another boat from Coral beach.

I would consider a room or chalet in Long beach instead. But it's up to you.