。
She has a delightful sense of humor.
Literal
She [topic-は] delightful humor [attributive-の] sense [subject-が] exists.
ユーモアのセンス is a calque on English 'sense of humor' — both ユーモア and センス are loanwords (from English humor and sense respectively), arranged in Japanese particle structure with の linking them. The pattern is common: katakana borrowings stitched together with の to form compound concepts (ファッションのセンス 'sense of fashion,' バランスの感覚 'sense of balance'). 楽しい ('fun, delightful') modifies the whole humor-noun-phrase. ~がある is the existential-possession construction for abstract qualities ('have / possess'), broader than 持っている which leans toward concrete possession.