>but according to VRRP both computers must share common default gateway of vrrp-ip.
That is correct.
In your scenario, each PC is on a different network (VLAN). This means that each switch will need a VLAN 3 and a VLAN 4 interface (with IP address, of course). Then each switch will need two VRRP instances with a defined VRRP IP address.
Switch 1:
VLAN 3 IP: 10.3.3.3
VLAN 4 IP: 10.4.4.2
Switch 2:
VLAN 3 IP: 10.3.3.5
VLAN 4 IP: 10.4.4.4
VRRP address for VLAN 3: 10.3.3.1 (this will be the DG for PC 1)
VRRP address for VLAN 4: 10.4.4.1 (this will be the DG for PC 2)
Also make certain that spanning tree is on!