If you're using an SH cluster, changing this manually in savedsearches.conf on the filesystem in one indexer, it may well be overwritten again when making a change in the GUI on another indexer. This is because manual changes are not replicated in the SH cluster.
Instead make the change using the GUI: Settings -> make sure you have 'Show All Settings' turned on -> Searches, reports, and alerts -> find the line with your search -> Advanced edit. There you'll find
display.visulaizations.show too and can change it.