The function for my eight trigrams mapping to "ahead eight trigrams"

[Thomas6]

This is the so-called Fuxi's "ahead eight trigrams" diagram. Ordinal numbers of his trigrams are as follows:
2 1 5

3 ******* 6

4 8 7


I created a diagram to revise King Wen's diagram. The ordinal numbers of trigrams in my diagram are as follows:
5 8 7

6 ******* 2

3 4 1

I need a function that maps Fuxi's diagram to my diagram. In short, it is to find the general terms formula of the sequence below:
8,5,6,3,7,2,1,4
thanks.