The Lewis diagram for SF3CN is a good representation of the molecule's bonding structure. In this Lewis diagram, the sulfur atom (S) is in the center of the molecule and is bonded to three fluorine atoms (F) and one cyanide group (CN).
The carbon atom (C) in the cyanide group is triple bonded to the nitrogen atom (N). The fluorine atoms are all terminal, meaning that they are each bonded to only one other atom.
The Lewis diagram for SF3CN shows that the sulfur atom has a valence electron count of 12. This is because the sulfur atom has six valence electrons and is bonded to three other atoms, each of which contributes one electron to the bond. The fluorine atoms each have a valence electron count of 7, and the nitrogen atom has a valence electron count of 5. The carbon atom has a valence electron count of 4, but because it is triple bonded to the nitrogen atom, it effectively has a valence electron count of 2.
However, it is important to note that Lewis diagrams do not take into account the molecule's three-dimensional structure. The actual structure of SF3CN is a bit more complex, and the sulfur atom is not actually bonded to all of the fluorine atoms in the same way.