app/views/devise/invitations/new.html.erb
<h2><%= t "devise.invitations.new.header" %></h2>
<%= simple_form_for resource, :as => resource_name, :url => invitation_path(resource_name), :html => {:method => :post} do |f| %>
<%= devise_error_messages! %>
<%= f.input :name %>
<%= f.input :email %>
<%= f.input :role %>
<%= f.submit t("devise.invitations.new.submit_button") %>
<% end %>