Laravel displaying elements distinctly

public function employeebanvisitor(Request $request) { 
    $vis = bookingmodel::distinct('visitorname')
        ->select(
            'id',
            'visitorname',
            'visitorphonenumber',
            'compname',
            'designation'
        )
        ->where('empmail',Auth::user()->email)
        ->get(); 
    return view('employee.employeebanvisitor',compact('vis')); 
}

In the above query i need to display the list distinctly where the the distinct element is visitorname.But this command does not return elements distinctly.Any Help or suggestion is most welcomed.

via Chebli Mohamed