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