Goto Admin > Settings > All Settings > Custom CSS and paste this:
.secondary-slider-wrapper {
display: grid;
grid-template-columns: repeat(auto-fill, minmax(75px, 1fr));
grid-gap: 1em;
}
To get the best results, you will need to create Store Category Slider images that have the Label/Name you want to display on the Image itself, and disable the "Show Store Category Slider Label" from Admin > Promotions > Store Category Slider