One vertex per element, one color per generator, with an edge from x to x·s.
(5,6,9,10)(7,8,11,12)(13,14)(15,19)(16,18)(17,20)(21,22,25,28)(23,27,24,26)(2,4)(6,10)(8,12)(13,14,16,18)(15,17,20,19)(1,2)(3,4)(21,23,25,24)(22,26,28,27)(5,7)(6,8)(9,11)(10,12)(13,15)(14,17)(16,20)(18,19)(21,22)(23,26)(24,27)(25,28) involution — undirected(5,8)(6,11)(7,10)(9,12)(13,14)(15,19)(16,18)(17,20)(21,24,25,23)(22,27,28,26)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.