According to the following graphs below, they are isomorphic. The matching pairs of the isomorphic graphs below are:
a - 7
b - 3
c - 5
d - 4
e - 1
f - 2
g - 6
However, I have the following:
a - 4
b - 3
c - 5
d - 7
e - 1
f - 2
g - 6
Unless I made a mistake. Thank you.

Also, is it possible to use compare adjacent matrices of each graph to see if Isomorphism exists (To be able to check in a faster rate rather than use trial and error)? Thank you
Yes, this happens. Your solution is correct. There can generally be more than one isomorphism between different graphs, just as there can be more than one bijection between two sets, or isomorphism between two groups, or homeomorphism between two topological spaces.