It's important to understand that:
* Syllabaries are not the primary writing system for Chinese. Chinese uses logographic characters, where each character typically represents a whole word or morpheme.
* Cantonese is a dialect of Chinese, not a separate language. While it has its own distinct pronunciation, it uses the same logographic writing system as other Chinese dialects.
Therefore, the idea of a syllabary specifically for Cantonese pronunciation is unlikely. It's possible there are modern phonetic transcriptions of Cantonese words or pedagogical materials using a syllabary-like format, but these are not traditional writing systems.
If you have more specific information about this "syllabary," please provide it, and I can offer a more focused answer.