One vertex per element, one color per generator, with an edge from x to x·s.
(2,4)(5,6,9,12)(7,11,8,10)(13,14,17,16)(15,19,20,18)(21,22,25,23)(24,26,28,27)(5,7,9,8)(6,10,12,11)(15,20)(18,19)(21,23,25,22)(24,26,28,27)(13,15)(14,18)(16,19)(17,20)(21,24,25,28)(22,26,23,27)(1,2)(3,4)(5,6)(7,10)(8,11)(9,12)(13,15)(14,18)(16,19)(17,20) involution — undirected(5,8,9,7)(6,11,12,10)(13,16,17,14)(15,19,20,18)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.