{% load socialaccount %}

{% for provider in socialaccount.providers %}
  <li>
    <a title="{{provider.name}}" class="socialaccount_provider {{provider.id}}"
       href="{% provider_login_url provider.id process=process scope=scope auth_params=auth_params %}">
      <i class="fa fa-{{ provider.id }}"></i>{{ provider.name }}
    </a>
  </li>
{% endfor %}

{% load socialaccount %}

{% for provider in socialaccount.providers %}
  <li>
    <a title="{{provider.name}}" class="socialaccount_provider {{provider.id}}"
       href="{% provider_login_url provider.id process=process scope=scope auth_params=auth_params %}">
      <i class="fa fa-lg fa-{{ provider.id }}"></i>&nbsp;&nbsp;&nbsp;{{ provider.name }}
    </a>
  </li>
{% endfor %}

Add FA icons to allauth snippet
Add FA icons to allauth snippet
