If I understand correctly, the scatter function (or a combination of scatter and plot if you want the points connnected with lines) would likely work.
Example —
T1 = array2table([rand(20,2) randi(4, 20, 1)], 'VariableNames',{'X','Y','Activity'})
Ua = unique(T1.Activity);
figure % Specific Number Of Unique 'Activity' Values & Legend Entries
hold on
for k = 1:numel(Ua)
vk = T1.Activity == k;
hs{k} = scatter(T1.X(vk,:), T1.Y(vk,:), 25, T1.Activity(vk,:),'filled');
end
hold off
grid
colormap('turbo')
legend([hs{:}],compose('Activity %d',Ua), 'Location','best')
figure % Any Number Of Activity Values, Optionally Connectyed By Lines, No Specific LEgend
scatter(T1.X, T1.Y, 25, T1.Activity,'filled')
hold on
plot(T1.X, T1.Y, ':k')
hold off
grid
colormap('turbo')
Make appropriate changes to get the result you want
.
