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