Here is a blank coloring page for teaching students the /s/ sound at the beginning level.
Students color this page after finishing the "Articulation Mouth for S" which can be found here alone:
or here, paired with "th" for comaparison/contrast:
The /s/ is sometimes articulated laterally or interdentally as a "th" sound.
Included is a blank version so your students can color the page and take it home to put up on their wall to practice!
Print as many as you like and keep them on hand!