Commentary
زَيَّنَّا لَهُمْ أَعْمَالَهُمْ (We have made their deeds adorned in their sight - 27:4)It means that those who do not believe in the Hereafter We have made their bad actions look adorned in their sight. Therefore they feel good about them and remain enthralled in depravity. Some commentators have interpreted that "their deeds" is used in this verse for good deeds. Hence meaning of the verse is that Allah had placed the good deeds before them with all their attractions. But those unjust people did not pay any attention to them, rather they remained engrossed in infidelity; hence lost their way in wilderness.
However, the first interpretation looks more appropriate and straightforward. In the first place, in the Qur'an, the word (Zinah) 'adornment' has been generally used for bad actions, for instance: زُيِّنَ لِلنَّاسِ حُبُّ الشَّهَوَاتِ (It has been made attractive for people to love the desires - 3:14) زُيِّنَ لِلَّذِينَ كَفَرُوا الْحَيَاةُ الدُّنْيَا (Adorned is the present life for those who disbelieve - 2:212) زَيَّنَ لِكَثِيرٍ مِّنَ الْمُشْرِكِينَ (6:137). Its use for good actions is very rare , such as: وَلَـٰكِنَّ اللَّـهَ حَبَّبَ إِلَيْكُمُ الْإِيمَانَ وَزَيَّنَهُ فِي قُلُوبِكُمْ (But Allah has endeared to you belief, decking it fair in your hearts - 49:7). Secondly, the word اَعمَالَھُم (their deeds) used in the verse is also pointing out that bad actions are meant here and not the righteous actions.