Best recommendation for traveling from Rome to Positano Italy?

No real easy way that I know about...

1) Roma Termini station to Napoli Centrale, 22 Euro apiece. Private driver to Positano will be expensive, no doubt more than 100 Euro, but might be worth it. Otherwise, it's Circumvesuviana train from Napoli Centrale to Sorrento station, then bus from there to Positano, which would be a lot cheaper.

2) Roma Termini to Salerno Centrale, then go to adjacent station for bus to Amalfi, at which time you'd change buses to Positano.

Depending on time of year, there is a hydrofoil from Naples to Positano or Salerno to Positano, which would be somewhat quicker and more scenic for sure.

In addition to the options above via train then bus or boat, there is also an all bus option from Roma to Sorrento com Marozzi bus company:

http://www.marozzivt.it/prenotazioni?tipologia=emissione&from=ROMA&to=SORRENTO&date_from=23-03-2017&date_to=

Then followed by the SITA bus from Sorrento to Positano (or the ferries at certain times of the year)
http://theamalficoast.online/orari_sita_bus_timetables.html

The Marozzi bus (departing from Roma Tiburtina takes 4 hours, so longer than the trains, but there are no changes and the luggage goes in the belly of the bus.

I had the same question...how many hours will it take from Rome to Positano given the options above? Is it an all day traveling?

Jessica--

Yeah, pretty much all-day travel depending on how much you want to spend.

Fastest would be Freccia train Rome/Naples (90 min), then a (pricey) private driver to Positano (2 hrs). If you can get into Naples Centrale, immediately take a taxi to the ferry and catch one to Positano (2 hr 40 min), that's next best case scenario from a time standpoint, somewhat cheaper.

Otherwise, it's going to take anywhere between 4-6 hours with changes, etc. Certainly doable, though.