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