It's possible the port number is incorrect. Which port are you using?
Do you still have Tableau Desktop 9.2 or 9.3 installed? What are the results of attempting to connect to Presto from 9.3 on the same machine that has 10.0 installed?
As the Tableau support says it works only with Teradata Presto and no other version of Presto distribution. We have Cloudera Presto 141.