Diagrams for the one-piece triangle module may be purchased separately as a file download, or can be found in the e-book "How to stretch a dodecahedron", or can be found in "3-D Geometric Origami" or in "Multi-modular Origami Polyhedra", both published by Dover. Instructions for making equilateral triangles may also be found in the two books mentioned published by Dover.
The size of the finished model, when made from modules folded from equilateral triangles with an altitude of 2.75", is 4.938" long with a diameter at the center of 3.625".
Subassemblies are color coded so that they may be identified in the finished model. When you understand the assembly procedure you can use any colors you want.