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