In the WooCoomerce admin backend open, WooCommerce -> Settings -> Group Attributes -> Styling: Layout
Select the desired layout option. To get a visual overview of the different layouts please visit the WUPO Group Attributes page
Create your own template
In the WooCoomerce admin backend open, WooCommerce -> Settings -> Group Attributes -> Styling: Layout and select a layout option higher than '1' (eg. Layout 2, or Layout 3)
Copy the corresponding PHP template file from /wp-content/plugins/wupo-group-attributes-pro/public/templates to your child theme directory in /wp-content/themes/<child-theme>/wupo-group-attributes-pro/public/
Adapt the copied PHP template file to your needs
Activating the WordPress debug mode will log additional information which helps to understand the received array with all attribute data