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