I did this

edit.blade.php

		{{ Form::model($role->first(), ['role' => 'form', 'url' => '/admin/roles/' . $role->first()->id, 'method' => 'PUT']) }}
			<div class='form-group'>
				{{ Form::label('name', 'Nome') }}
				{{ Form::text('name', null, ['placeholder' => 'Nome', 'class' => 'form-control']) }}
			</div>			
			@foreach ($perms as $perm)
				<div class='form-group'>
					{{Form::label('perm_name'.$perm->id, $perm->name );}}
					{{Form::label('perm_name_d'.$perm->id, $perm->display_name );}}
					{{Form::checkbox( $perm->id, $perm->id, $permRole->contains($perm->id) ? 1 : 0); }}
				</div>
			@endforeach
			<div class='form-group'>
				{{ Form::submit('Actualizar', ['class' => 'btn btn-primary']) }}
			</div>
		{{ Form::close() }}

Controller.php

edit function

		$perms = Permission::all();
		$role = Role::whereId($id)->get();
		$permRole = $role->first()->permissions()->get();
		return View::make('admin.roles.edit', [ 'role' => $role, 'perms' => $perms, 'permRole' => $permRole ]);

update function

		$permissions = Permission::all();
		$role = Role::find($id);
		$role->name			= Input::get('name');
		$role->save();
		$role->permissions()->detach();
		foreach ($permissions as $key) {
			if (Input::has($key->id)) {
				$role->permissions()->attach($key->id);
			}
		}
		return Redirect::to('/admin/roles');