External Drive icons missing on Apple
When you use that method of mounting an NTFS volume as writeable, the icon no longer shows up in the Finder.

Navigate to /Volumes and you'll find the drive icon there.

I've experienced data loss using that method, so would recommend that you use ntfs-3g or one of the commercial solutions [Paragon or Tuxera]

Some discussion here:
Write to NTFS-formated drives on Yosemite