As per Vastu Experts, toilet should strictly not be there in center of the home, NE or SW direction.
You can have toilet in the east direction.
For attached toilet SE is not a preferred location for the toilet.
Few guidelines for toilet:
Toilet seat should be in south to north or west to east direction
Mirrors must be located on the north or east walls
Toilets must be in north-west or west direction of the house or building
If the toilet is attached then it must be in north-west direction of the room
Light shades mostly preferred in toilet rather than red and black
I have also noticed few more similar Q&A
What Vastu tips are there to decide about Bathroom or toilet?
http://community.vastudekho.com/358/what-vastu-tips-are-there-to-decide-about-bathroom-or-toilet
What direction a person should face while sitting in the toilet?
http://community.vastudekho.com/171/what-direction-person-should-face-while-sitting-the-toilet