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