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