By plane:
Zipolite is located midway between the airports of Puerto Escondido and Huatulco, about an hour from either, to come to Zipolite you can take a taxi at the airport, which is more expensive, or take a taxi outside the airport which is less expensive, The airlines aeromexico,  interjet and viva aerobus have daily flights, and give special rates booking ahead of time.
By Bus:
Leaving Mexico City there are two bus lines that come out at night to Pochutla (twenty minutes from Zipolite) one leaves from Taxqueña terminal and the other from the North terminal, Futura, Primera Plus and Cristobal Colon are the lines that travel to this area.
From Oaxaca City you can take the famous “suburbans” which leave from downtown and come to Pochutla in five hours.
From Mexico City, you can take the road  to Acapulco  then take the deviation towards Pinotepa Nacional, this road takes you directly to Puerto Escondido and Huatulco, between these cities you will see the diversion to Puerto Angel, Zipolite and Mazunte.
You can also come via Tehuacan, Puebla, drive to the city of Oaxaca and then to Pochutla to follow the coast via Puerto Angel.