It depends on which of the two Orlando Sheraton's Vistana timeshares you're asking about.
Sheraton's Vistana Villages is roughly across International Drive from Floriday's Resort, probably about half a mile from within Floriday's to within Vistana Villages but you have to be careful crossing I-Drive and I'm uncertain whether there are sidewalks along that section of the road.
Sheraton's Vistana Resort is on SR 535 about 3 miles from Floriday's.
Dick Taylor