We do not support SFTP on our shared hosting accounts because it requires opening up SSH to the world and we see this as a security risk, rather than a security mitigation.
We do however support FTPES (FTP over explicit TLS/SSL). The settings to use should be the same as long as your FTP client supports this except that you need to select the FTPES option for the protocol.
This will only work if your FTP client supports it. A popular FTP client that does support FTPES is FileZilla (http://filezilla-project.org/)