Item categories list show on POS screen

Can anyone tell me how can I add item categories on the screen of POS please see the picture I have draw boxes where I need the item category icons when I click on the icon so the category items will display

i can’t see the image

i have attached the picture again please check i need item categories where i make the A buttons

i think you have to write some code to achieve this kind of view,
1- hide the item group select field
2- render item group as boxes so you select them by screen touch