It is important to note that not all education/teaching programs are accredited by NESA. Becoming a teacher in NSW requires completion of a NESA-accredited degree, a list of which can be found
here (sorted by university/educational institution). Because of this, diplomas and graduate diplomas in education/teaching are not NESA-accredited teaching degrees, but rather act as pathway programs for degrees that are accredited by NESA, examples of which include a Bachelor of Education and a Master of Teaching. You can still study a diploma or graduate diploma in education/teaching and subsequently complete a NESA-accredited teaching degree, although this could result in longer study duration.
If you are interested in primary school teaching, then a Bachelor of Education (Primary) is likely a good option, as it provides a good balance between gaining knowledge that encompasses the relevant subject areas at primary school level as well as the necessary knowledge and skills for primary school teaching. You could also study a Bachelor of Visual Communication Design (or similar) followed by a Master of Teaching (Primary) if you are interested in this field. In making an informed decision, you may wish to consider the more comprehensive degree between a Bachelor of Education (Primary) and a Bachelor of Visual Communication Design in terms of content, the reason being that you may be able to teach more subjects if either degree focuses on more subject areas than the other.
I hope this helps!