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